1. Field of the Invention
The present invention relates generally to a seal and, more particularly, to a seal for use in a positive displacement meter.
2. Description of Related Art
Positive displacement water meters and water meters in general, have several criteria that must be met. They must be accurate and they must be able to function in various temperatures. Debris floating in the water, be it rust or other objects, can affect the operation of water meters, particularly positive displacement meters. Hence, all positive displacement meters include at least a filter screen preferably positioned forwardly of the positive displacement meter chamber. In many instances, the positive displacement meter chamber must be held between a gasket and meter body. If the meter chamber is compressed too tightly, it will affect accuracy of the meter and may cause the measuring chamber piston to bind. Further, in many instances, the meters may be placed in cold environments where the water will freeze. This can typically happen in a home where the heat is shut off. In that case the meter body may be damaged. To minimize this effect, meter bottom plates are provided made of cast iron or plastic. However, if the cast iron meter bottom plate does not fail at the appropriate time, the meter casing and measuring chamber will be damaged.
Additionally, an outlet port is defined within the measuring chamber of the positive displacement water meters. The outlet port typically abuts a meter casing of the positive displacement meter with a seal situated therebetween. However, the design of prior art seals allows the seals to become loose and dislodge during the assembly of the meter. Further, the prior art seals leaked due to pressure pulses and back syphonage during the meter operation.
Therefore, it is an object of the present invention to provide a meter to overcome the deficiencies of the prior art.